"Octopus buns" may be a ~thing~ right now, but slightly tousled, messy topknots have always been a standby gym hairstyle. (Here are some less-traditional gym-friendly dos.) The messy bun is meant to look effortless, but anyone who's spent a few minutes in front of the mirror trying to make their hair perfectly imperfect knows there's a true art to styling one. Nailing the placement, size, and degree of messiness can be tricky. Try this foolproof method for how to do a perfect messy bun that will stay put through a workout, and look great even if you skip a post-sweat-sesh shower.

1. Skip the Brush

"Use your hands to pull your hair into a ponytail at the crown of your head," says Matt Fugate, a consulting hairstylist for Kérastase. "This keeps some texture in your hair, which looks cool and helps hide sweat." If your hair appears more oily than sexy, spritz a powder volumizer, like Kérastase V.I.P. ($20; kerastase-usa.com), into the roots to soak up moisture and add lift. Then redo the ponytail.

2. Work on Your Body

Mist your ponytail with a texture spray, like AG Hair Tousled Texture ($24; ulta.com), then run your fingers up the hair to gently tease it (or use one of these tricks to boost volume). Ruffling it a bit adds volume, which will make your bun bigger, Fugate explains. Now wrap the hair around the base of the pony.

3. Stick the Landing

A few bobby pins slipped into the bun will hold it securely. "But I also allow some strands to fall out. The look seems more effortless that way," Fugate says. To make sure those pieces don't get frizzy, spray a bit of dry oil, like Garnier Fructis Sleek & Shine Zero Smoothing Light Spray ($5; garnierusa.com), into your palms, then run them over the errant tendrils.